The invention relates to a rolling element bearing system comprising at least one rolling element bearing with an outer race and an inner race which enclose a space containing rolling elements, which space is confined to the outside by means of sealing rings. Such rolling bearings are generally known. The rolling elements as well as the raceways of the races are protected against contaminations by the sealing rings so as to provide an acceptable service life.
In specific applications it is sufficient to introduce an amount of grease into said space, which stays there during the entire life of the bearing. In other applications however, such kind of lubrication is not sufficient, in particular for bearings applied in gear boxes or more in general in power transmissions. Such transmissions are oil bath lubricated; the sealing rings however prevent the inflow of splash lubricant into the bearing. This leads in some cases to a fast aging of the lubricant inside the bearing space.
If however in such cases a less tight sealing would be applied, or the sealing rings would be omitted altogether, any contaminations which accumulate in the oil due to wear of the transmission components such as tooth gears, would enter the bearing space and seriously deteriorate the capacities of the bearing.
Furthermore, in many cases it is necessary to control the amount of lubricant which is present in the bearing space in order to minimize friction losses.